1. Field of the Invention
The present invention generally relates to an actuating mechanism able to accomplish a plurality of different works independently by the operation of a single motor, and particularly relates to the actuating mechanism for switching and transmitting a driving force to a desired mechanism provided in a camera.
2. Description of the Related Arts
Conventionally, there have been provided some types of actuating mechanisms. Taking actuating mechanisms shown in Japanese Laid-Open Patent (Unexamined) Publication Nos. 1-287648 and 3-208033 (FIGS. 8-11 in particular) for examples, a sun gear is connected to an output shaft of a motor, planetary gears are revolved around the sun gear, and a driving force can be switched and transmitted to any desired one of driving stations via one of the planetary gears.
In the former conventional art, a plurality of planetary gears is provided in one-to-one correspondence to respective station gears; namely, there are provided planetary gears equal in number to the station gears. Furthermore, the actuating mechanism is constructed so that one rotational direction of the motor makes each planetary gear revolve, while the other rotational direction thereof makes each planetary gear rotate on its axis. Accordingly, it is only in one direction that each planetary gear can rotate on its axis, and it is not possible to transmit to each station gear the driving force enabling it to rotate in both directions.
In the latter conventional art, it is possible to drive each station gear in both rotational directions, because the revolution of one planetary gear can lead to switching from one station gear to another, and because the movement of its planetary carrier is restrained with the planetary gear engaging the station gear. However, because the restraint or unrestraint of the planetary carrier with respect to each station gear is performed by using a driving source different from one for driving the actuating mechanism itself, and because a large power is required to move the restraining member on which a load due to the driving is imposed and to overcome its friction, a large and expensive plunger must be used in the actuating mechanism. Employing such a large and expensive plunger acts as a disadvantage in providing a smaller and cheaper actuating mechanism.